In the phosphate mining complexes that manufacture wet process phosphoric acid, water is employed as a coolant for gas streams and other process uses within the complex. The water absorbs and dissolves various materials during these uses and is then sent to ponds for cooling. The pond water created is contaminated, acidic and is no longer able to be discharged to the surrounding environment due to various federal and state limits on many of the contaminants found in the pond water, including fluoride and phosphate compositions. Typical pond water has a pH in the range of 1.2–2.0, a phosphate content of 15,000–22,000 parts per million (ppm), fluoride compounds at a levels of 5000–10,000 ppm and total dissolved solids up to 50,000 ppm. As the phosphoric acid plant operates, the pond water continues to accumulate in large quantities until all storage capacity is exceeded. The phosphate manufacturer must then go through an expensive treatment process to meet federal and state limits before discharging the pond water to the environment.
The phosphate manufacturers create large ponds which are hundred of acres in size to contain and store the contaminated pond water and then rely on natural evaporation and expensive treatment processes to treat and then release the treated pond water to the surrounding environment. The invention can also reduce the amount of fresh water used by the power plant.